The extent of exposure to secondhand tobacco smoke (SHTS) is a significant predictor of the prevalence and extent of coronary artery calcification, according to a landmark research study by a team of radiologists and cardiologists at The Icahn School of Medicine at Mount Sinai.

Previously, scientific evidence supported a causal association between SHTS and coronary artery calcification mortality and morbidity. However, this study, conducted in association with the Flight Attendant Medical Research Institute International Early Lung Cancer Action Program (FAMRI-IELCAP) marks the first time low-dose, nongated CT scans have been used to assess this association. It is also the first to show the quantitative dose relationship of SHTS to a type of coronary artery disease.

The findings will be presented at the American College of Cardiology’s Scientific Sessions, and published online by JACC Imaging, a journal of the American College of Cardiology (ACC). The study was presented at the ACC conference by Harvey Hecht, MD, Associate Director of Cardiac Imaging at The Mount Sinai Medical Center and Professor of Medicine at the Icahn School of Medicine at Mount Sinai and Jagat Narula, MD of Mount Sinai Heart.

"As the debate continues to rage concerning the early detection of all types of cancer, this study reminds us that carefully analyzed, low-dose CT scan screening may provide secondary information of potentially equal importance in prolonging a healthy life,” said Burton Drayer, MD, the Dr. Charles M. and Marilyn Newman Professor and Chair of the Department of Radiology at the Icahn School of Medicine at Mount Sinai.

Researchers from Mount Sinai found that 24 percent of study participants (754) had CAC, with rates significantly higher in the sub-groups with more than minimal (low, moderate and high) exposure to SHTS. They concluded that the presence and extent of CAC was associated with the extent of secondhand tobacco smoke exposure, even when adjusting for other risk factors for coronary artery calcification. The study suggests that SHTS exposure causes CAC.

“FAMRI’s dedication to understanding the harm due to secondhand tobacco smoke have made this important contribution to a widening body of research possible,” said Claudia Henschke, MD, the Principal Investigator of the FAMRI-IELCAP Center of Excellence at Mount Sinai and the Director of the Lung and Cardiac Screening Program at Mount Sinai Medical Center and a Professor of Radiology at the Icahn School of Medicine at Mount Sinai.

Study participants in the FAMRI-IELCAP CT screening program had no prior history of, and were asymptomatic for, coronary artery disease. Researchers also performed logistic regression analyses, adjusting for age, gender, diabetes, hypercholesterolemia, hypertension and renal disease.

“As medical professionals, we must help heighten awareness about the negative health effects of passive smoking, as well as indoor and outdoor pollution,” said Dr. Narula. “And from a public health perspective, we must also campaign more vigorously against the tobacco industry and do everything possible to lessen – and eliminate – the allure of smoking among people young and old. Studies like this, along with other measures, are critical tools in achieving those goals.”

“This research provides additional evidence that secondhand smoke is harmful, and may be even more dangerous that we have thought,” said Dr. Hecht. “We actually found the risk of secondhand smoke exposure to be an equivalent or stronger risk factor for CAC than other well-established ones such as high cholesterol, hypertension and diabetes.”

“We are reminded that the risks from tobacco occur not only to the smoker, but also to those exposed to their secondhand smoke – and that SHTS can also affect not only the lungs, but the heart as well,” said the first author of the study, David Yankelevitz, MD, Director of the Lung Biopsy Service at the Mount Sinai Medical Center and a Professor of Radiology at the Icahn School of Medicine at Mount Sinai.